Three studies of headache features in migraine, cluster and tension headaches were developed based on the data collected from a feasibility study for a survey of headache (Z01 NS 02404-07). The feasibility study involved 243 patients from four headache clinics. The first study used four group discriminant analysis to develop statistically a parsimonious set of headache features and symptoms which could be used to correctly classify a high percentage of patient headaches into one of the four headache types of common migraine, classical migraine, cluster or tension headache. A second study using factor analysis, on the combined group of headaches, attempted to isolate patterns of symptoms and features of headaches which mirror clinical descriptions of the four headache types above. The study yielded indeterminate results. The third study, describes for each headache type, the frequency of and interrelationships among headache symptoms and features, and relates precipitating factors such as eyestrain, menstruation, etc., to these patterns.